Lee Min Ho, Lee Hyun Seok, Jee Tae Keun, Jo Kyung Il, Kong Doo-Sik, Lee Jeong A, Park Kwan
Department of Neurosurgery, Samsung Medical Center, School of Medicine, Sungkyunkwan University, 81 Irwon-ro, Gangnam-gu, Seoul, 135-710, Korea.
Acta Neurochir (Wien). 2015 Feb;157(2):337-43. doi: 10.1007/s00701-014-2301-8. Epub 2014 Dec 18.
This retrospective study evaluated the length of cerebellar retraction and the changes of intraoperative brainstem auditory evoked potential (BAEP) during microvascular decompression (MVD), and assessed the predictive value of the hearing loss as a prognostic indicator for the treatment outcome of hemifacial spasm (HFS).
This series included 1,518 consecutive patients affected with HFS who underwent MVD, during which BAEP was monitored. Patients were divided into two groups based on whether hearing loss occurred following decompression or not. Each patient underwent a similar procedure performed by one neurosurgeon. The two patients groups were matched with regard to sex, age, and degree of spasm.
Among the 1,518 patients, 106 (6.98 %) displayed functional hearing changes. Hearing loss was permanent in 12 patients (0.79 %). Of the 1,412 patients with stationary hearing compared with preoperative audiometry, 96 patients were selected who were individually matched with respect to sex, age, and degree of spasm. BAEP changed immediately after cerebellar retraction in 7 of 12 hearing-loss patients, suggesting the importance of retraction on hearing outcomes. The distance from the cerebellar surface of the petrous temporal bone to the neurovascular compression point was measured. The median distance of cerebellar retraction in the hearing-loss group was 13.77 mm, which was longer than the median distance in the control group.
Preoperative measurement of the cerebellar retraction distance can be a valuable clue to predict and prevent postoperative hearing loss in MVD for HFS.
本回顾性研究评估了微血管减压术（MVD）期间小脑牵拉的时长及术中脑干听觉诱发电位（BAEP）的变化，并评估了听力损失作为面肌痉挛（HFS）治疗结果预后指标的预测价值。
本系列研究纳入了1518例连续接受MVD治疗的HFS患者，术中监测BAEP。根据减压后是否发生听力损失将患者分为两组。每位患者均由一名神经外科医生进行类似的手术。两组患者在性别、年龄和痉挛程度方面进行匹配。
在1518例患者中，106例（6.98%）出现功能性听力改变。12例患者（0.79%）听力损失为永久性。在1412例与术前听力测定相比听力稳定的患者中，选择了96例在性别、年龄和痉挛程度方面进行个体匹配的患者。12例听力损失患者中有7例在小脑牵拉后BAEP立即发生改变，提示牵拉对听力结果的重要性。测量了颞骨岩部小脑表面至神经血管压迫点的距离。听力损失组小脑牵拉的中位距离为13.77mm，长于对照组的中位距离。
术前测量小脑牵拉距离可为预测和预防HFS的MVD术后听力损失提供有价值的线索。
